The present invention relates to a machine and a method for fastening a load. More particularly, the present invention relates to the fastening of the load by means of a rope made from a roll of flexible material such as for example plastic film.
The load can be for example a metal coil on a pallet. According to the prior art, such a metal coil is strapped down on the pallet by means of steel straps. Then, sometimes, the metal coil is further wrapped by means of a stretched film to protect it during transportation or in the case where it is stored outside. The strapping of the metal coil on the pallet by means of steel straps is done manually or automatically.
Known in the art, there is the U.S. Pat. No. 4,271,657 granted on Jun. 9, 1981 to Patrick R. LANCASTER, III. This patent describes an apparatus and process for automatically making a spiral wrapped unitary package having a ring type or tied closure. In the apparatus, a series of loads, each containing a plurality of units are fed one load at a time onto a turntable adjacent a material dispenser with the leading edge of the material from the dispenser being formed into a rope-like configuration by a roper mechanism and held by a clamp mechanism mounted on the turntable. The material is open to its full web width, stretched and is spirally wrapped around the load at which time it is again formed into another rope-like configuration by the roper mechanism, and is positioned adjacent the leading edge where it is mechanically joined to the leading edge of the material by a ring type or tied closure. The roped material is then released from the clamp mechanism mounted on the turntable and the material is allowed to return to its memory position. The clamp mechanism again clamps the leading edge for the next load and the material is severed from the wrapped load.
Also known in the art, there is the U.S. Pat. No. 5,107,657 granted on Apr. 28, 1992 to Werner K. DIEHL et al. This patent describes an apparatus for wrapping a pallet load with a wrapping film applied selectively as a film rope or as a film sheet. The load is supported in an elevated position. A rotary arm supported above the load is arranged to be rotatably driven. An upright member depending from the rotary arm is spaced outwardly from the load in any rotary arm position. A carriage is arranged to be upwardly and downwardly driven along such member. A dispenser on the carriage dispenses the wrapper as a rope or as a sheet. A guide, which comprises a lever and a hook on the lever, is moveable among extended, partly retracted, and fully retracted positions. In the extended position, the guide guides the rope across the respective corners of the load. In the partly retracted position, the guide does not interfere with driving the carriage along the upright member.
Also known in the art, there is the U.S. Pat. No. 4,631,898 granted on Dec. 30, 1986 to Dario BRAMBILLA. This patent describes a process and an apparatus for continuously wrapping a palletized load, a self-propelling apparatus is provided, said apparatus being fitted with means for electric traction fed by batteries, said machine moving at a distance around the outer perimeter of a load.
Also known in the art, there are the following U.S. patents which describe different methods and apparatuses for wrapping a load: U.S. Pat. Nos. 4,299,076; 4,432,185; 4,691,497; 4,831,812; 5,005,335; 5,054,263; 5,168,691; 5,301,493; 5,408,808; 5,423,163; 5,450,709; 5,606,849; 5,623,808; 5,628,167; 5,701,722; 5,794,418; 5,787,691; 5,802,810; and 5,836,140.
None of the above-mentioned patents provides the necessary means for fastening loads having a large range of sizes, rapidly and efficiently.
It is an object of the present invention to provide a method and a machine for fastening loads having range of sizes larger than those of the prior art, in a rapid and efficient manner.
According to the present invention, there is provided a machine for fastening a load having a given size, comprising:
a machine frame positioned around a central axis intersecting a point where, in operation, the load is brought;
a delivering carriage onto which a roll of flexible material is rotatively mountable, including an output delivering means for delivering the flexible material as a rope;
first controllable moving means for producing a relative radial movement of the output delivering means with respect to the central axis;
a second controllable moving means for producing a relative rotating movement of the rope with respect to the central axis;
a third controllable moving means for producing a relative axial movement of rope in a direction parallel to the central axis; and
controlling means for controlling:
the relative radial movement by means of the first controllable moving means in view of the size of the load; and
the relative rotating and axial movements by means of the second and third controllable moving means to fasten the load with the rope once the radial movement has been produced.
Also according to the present invention, there is provided a method for fastening a load having a given size, comprising:
(a) bringing the load to a point intersected by a central axis;
(b) after step (a), producing a relative radial movement of an output delivering means with respect to the central axis in view of the size of the load, the output delivering means being for delivering a flexible material;
(c) delivering the flexible material as a rope by means of the output delivering means;
(d) after steps (b) and (c), producing a relative rotating movement of the rope with respect to the central axis; and
(e) during step (d), producing a relative axial movement of rope in a direction parallel to the central axis to fasten the load with the rope by means of the relative rotating and axial movements thereof.